Compact Mobile Cargo Scanning System

ABSTRACT

The present invention is a self-contained mobile inspection system and method and, more specifically, improved methods and systems for detecting materials concealed within a wide variety of receptacles and/or cargo containers. In particular, the present invention is an improved method and system with a novel boom structure that reduces the weight of the boom. The single, light-weight boom of the inspection system is relatively compact in a stowed configuration and has a low height and center of gravity lending to greater maneuverability.

CROSS-REFERENCE

The present invention relies on U.S. Provisional Patent Application No.61/180,471, filed on May 22, 2009, for priority.

The present invention is a continuation-in-part of U.S. patentapplication Ser. No. 12/339,591, entitled Rotatable Boom Cargo ScanningSystem, filed on Dec. 19, 2008, which is a continuation-in-part of U.S.patent application Ser. No. 11/948,814, entitled, “Single Boom CargoScanning System”, filed on Nov. 30, 2007, which is a continuation ofU.S. Pat. No. 7,322,745, entitled, “Single Boom Cargo Scanning System”,filed on Aug. 9, 2004, which relies on, for priority, U.S. ProvisionalPatent Application No. 60/493,935, filed on Aug. 8, 2003 and is acontinuation-in-part of U.S. patent application Ser. No. 10/201,543,entitled “Self-Contained Portable Inspection System and Method”, filedon Jul. 23, 2002 and now U.S. Pat. No. 6,843,599. The '591 applicationfurther relies on U.S. Provisional Application No. 61/014,814, filed onDec. 19, 2007, for priority. The '591 application is also acontinuation-in-part of U.S. patent application Ser. No. 12/051,910,entitled “Single Boom Cargo Scanning System”, and filed on Mar. 20,2008, which is a continuation of U.S. Pat. No. 7,369,463, of the sametitle, filed on Jan. 12, 2007, which is a continuation-in-part of U.S.Pat. No. 7,322,745.

The present invention is also a continuation-in-part of U.S. patentapplication Ser. No. 12/263,160, entitled “Cargo Scanning System”, andfiled on Oct. 31, 2008, which further relies on U.S. Provisional PatentApplication No. 60/984,786, filed on Nov. 2, 2007, for priority, and isa continuation-in-part of U.S. Pat. No. 7,322,745.

The present application is also a continuation-in-part of Ser. No.12/349,534, which is a continuation of U.S. patent application Ser. No.10/939,986, entitled “Self-Contained Mobile Inspection System”, andfiled on Sep. 13, 2004, which is a continuation-in-part of Ser. No.10/915,687 (issued as U.S. Pat. No. 7,322,745), which is acontinuation-in-part of Ser. No. 10/201,543 (issued as U.S. Pat. No.6,843,599) and further relies on U.S. Provisional Patent Application No.60/502,498, filed on Sep. 12, 2003, for priority.

All of the above-listed patent applications are herein incorporated byreference.

FIELD OF THE INVENTION

The present invention relates generally to a self-contained mobileinspection system and method and, more specifically, to improved methodsand systems for detecting materials concealed within a wide variety ofreceptacles and/or cargo containers. In particular, the presentinvention relates to improved methods and systems for inspectingreceptacles and/or cargo containers using a single boom which can befolded, such that the inspection system is light-weight and relativelycompact in a stowed configuration and has a low height and center ofgravity lending to greater maneuverability.

BACKGROUND OF THE INVENTION

X-ray systems are used for medical, industrial and security inspectionpurposes because they can cost-effectively generate images of internalspaces not visible to the human eye. Materials exposed to X-rayradiation absorb differing amounts of X-ray radiation and, therefore,attenuate an X-ray beam to varying degrees, resulting in a transmittedlevel of radiation that is characteristic of the material. Theattenuated radiation can be used to generate a useful depiction of thecontents of the irradiated object. A typical single energy X-rayconfiguration used in security inspection equipment may have afan-shaped or scanning X-ray beam that is transmitted through the objectinspected. The absorption of X-rays is measured by detectors after thebeam has passed through the object and an image is produced of itscontents and presented to an operator.

Trade fraud, smuggling and terrorism have increased the need for suchnon-intrusive inspection systems in applications ranging from curbsideinspection of parked vehicles to scanning in congested or high-trafficports because transportation systems, which efficiently provide for themovement of commodities across borders, also provide opportunities forthe inclusion of contraband items such as weapons, explosives, illicitdrugs and precious metals. The term port, while generally accepted asreferring to a seaport, also applies to a land border crossing or anyport of entry.

With an increase in global commerce, port authorities require additionalsea berths and associated container storage space. Additional spacerequirements are typically met by the introduction of higher containerstacks, an expansion of ports along the coastline or by moving inland.However, these scenarios are not typically feasible. Space is generallyin substantial demand and short supply. Existing ports operate under aroutine that is not easily modified without causing disruption to theentire infrastructure of the port. The introduction of new procedures ortechnologies often requires a substantial change in existing portoperating procedures in order to contribute to the port's throughput,efficiency and operability.

With limited space and a need to expand, finding suitable space toaccommodate additional inspection facilities along the normal processroute remains difficult. Additionally, selected locations are notnecessarily permanent enough for port operators to commit to the longterm installation of inspection equipment. Moreover, systemsincorporating high-energy X-ray sources, or linear accelerators (LINAC),require either a major investment in shielding material (generally inthe form of concrete formations or buildings) or the use of exclusionzones (dead space) around the building itself. In either case, thebuilding footprint is significant depending upon the size of cargocontainers to be inspected.

A mobile inspection system offers an appropriate solution to the needfor flexible, enhanced inspection capabilities. Because the system isrelocatable and investing in a permanent building in which toaccommodate the equipment is obviated, site allocation becomes less ofan issue and introducing such a system becomes less disruptive. Also, amobile X-ray system provides operators, via higher throughput, with theability to inspect a larger array of cargo, shipments, vehicles, andother containers.

Conventional relocatable inspection systems generally comprise at leasttwo booms, wherein one boom will contain a plurality of detectors andthe other boom will contain at least one X-ray source. The detectors andX-ray source work in unison to scan the cargo on the moving vehicle. Inconventional single boom relocatable inspection systems, the X-raysource is located on a truck or flatbed and the detectors on a boomstructure extending outward from the truck. These systems arecharacterized by moving-scan-engine systems wherein the source-detectorsystem moves with respect to a stationary object to be inspected. Also,the detectors and the source of radiation are either mounted on amoveable bed, boom or a vehicle such that they are integrally bound withthe vehicle. This limits the flexibility of dismantling the entiresystem for optimum portability and adjustable deployment to accommodatea wide array of different sized cargo, shipments, vehicles, and othercontainers. As a result these systems can be complicated to deploy andpose several disadvantages and constraints.

For example, in a moving-scan-engine system the movement of the sourceand detector, relative to a stationary object, may cause lateral twistand lift and fall of the detector or source, due to movement of thescanner over uneven ground, inducing distortions in the scanned imagesand faster wear and tear of the scanner system. Systems where the weightof the detector or source is held on a boom require high structuralstrength for the boom in order to have the boom stable for imagingprocess, thereby adding more weight into the system. Such systems thatrequire a detector-mounted boom to unfold during deployment may cause anunstable shift of the center of gravity of the system off the base,causing the system to tip over. Further, in the case ofmoving-scan-engine systems using a “swing arm” boom approach, the driverdriving the scanner truck is unable to gauge the possibility of hittingthe detector box, mounted on a boom, with a vehicle under inspection(VUI), as the detector box is on the other side of the VUI duringscanning and not visible to the driver.

Additionally, with moving-scan-engine systems, the truck supporting thescanner system is always required to move the full weight of the scannerregardless of the size and load of the VUI, putting greater strain onthe scanning system. Also disadvantageous in conventional systems isthat they suffer from a lack of rigidity, are difficult to implement,and/or have smaller fields of vision.

Accordingly, there is need for improved inspection methods and systemsbuilt into a fully self-contained, over-the-road-legal vehicle that canbe brought to a site and rapidly deployed for inspection. The improvedmethod and system can, therefore, service multiple inspection sites andset up surprise inspections to thwart contraband traffickers whotypically divert smuggling operations from border crossings that havetough interdiction measures to softer crossings with lesser inspectioncapabilities. Moreover, there is an additional need for methods andsystems that require minimal footprint to perform inspection and thatuse a sufficient range of radiation energy spectrum to encompass safeand effective scanning of light commercial vehicles as well assubstantially loaded 20-foot or 40-foot ISO cargo containers. It isimportant that such scanning is performed without comprising theintegrity of the cargo and should ideally be readily deployable in avariety of environments ranging from airports to ports of entry where asingle-sided inspection mode needs to be used due to congestedenvironments. Similar needs are addressed in U.S. Pat. No. 6,543,599,entitled “Self-Contained Portable Inspection System and Method”, whichis herein incorporated by reference in its entirety.

Improved methods and systems are additionally needed to keep therelative position between the radiation source and detector fixed toavoid distortion in images caused by the movement of scanner and/ordetectors over uneven ground or due to unstable structures. Moreover,there is a need for improved methods and systems that can providecomprehensive cargo scanning in portable and stationary settings.Specifically, methods and systems are needed in which a single boom isemployed for generating quality images for inspection. Further, thesystem should be mounted on a relocatable vehicle, capable of receivingand deploying the boom.

What is also needed is a single boom cargo scanning system that enablesquick and easy deployment, rigidity and tight alignment of the radiationsources and detectors, and a narrow collimated radiation beam, thusallowing for a smaller exclusion zone. In addition, what is needed is anoptimal scanning system design that allows for the radiation source tobe closer to the Object under Inspection (“OUI”), thereby allowing forhigher penetration capability and complete scanning of the targetvehicle without corner cutoff. Similar needs are addressed in the U.S.Pat. No. 7,322,745, entitled “Single Boom Cargo Scanning System” whichis herein incorporated by reference in its entirety.

Further, in the mobile cargo inspection systems known in the art, theboom structures are typically heavy, thereby causing the overall weightof the scanning system to be close to, or even over the allowable axleload limits. Further, the booms are bulky when stowed such that thevehicle is approximately 4 m high above road level. This makes a mobilescanning system not only difficult to manoeuvre but also restricts itsmovement in different territories due to the applicable roadrestrictions on carriage weight. Therefore, there is also a need for ascanning system that can be stowed in a relatively compact area so thatit can be easily transported on road, as well as by air. In addition,there is also a need for a scanning system which is light weight, andhas a low height and center of gravity in a stowed position, therebyallowing for road transport even in challenging, steep and hilly areas.

What is also needed is a scanning system that can be deployed from astowed configuration to an operational configuration in operating areashaving limited horizontal or vertical clearance.

SUMMARY OF THE INVENTION

The present invention is a self-contained mobile inspection system andmethod for detecting materials concealed within a wide variety ofreceptacles and/or cargo containers. In particular, the presentinvention is an improved method and system for inspecting receptaclesand/or cargo containers using a single boom that can be folded andunfolded, such that the inspection system is relatively compact in astowed configuration and has a low height lending to greatermaneuverability. This, and other embodiments of the present invention,shall be described in greater depth in the drawings and detaileddescription provided below.

In one embodiment, the present specification discloses an inspectionsystem comprising a vehicle having a first axle proximate to a front ofsaid vehicle and one or more rear axles proximate to a back of saidvehicle wherein a first area is bounded by the rear axle extending tothe front of said vehicle and a second area is bounded by the rear axleextending to the back of said vehicle; a radiological source; and a boomrotatably attached to said vehicle wherein said boom comprises a firstvertical section, a second vertical section and a horizontal section andwherein, when fully deployed, said boom defines an area having a heightin a range of 2000 mm to 5300 mm and a width in a range of 2000 mm to4000 mm, wherein said system weighs less than 20,000 kg and is capableof achieving radiological penetration of at least 30 mm of steel.Optionally, the minimum penetration can be 31 mm, 40 mm, 50 mm, 60 mm,120 mm or some increment therein.

The radiological source is attached to said vehicle. The radiologicalsource is attached to said vehicle but not attached to said boom. Theradiological source is an X-ray source is at least one of a X-raygenerator with 100 kVp to 500 kVp tube voltage and 0.1 mA to 20 mA tubecurrent, a 0.8 MV to 2.5 MV linear accelerator source with a dose outputrate of less than 0.1 Gy/min at 1 m, and a 2.5 MV to 6 MV linearaccelerator source with a output dose rate in a range 0.1 Gy/min at 1 mto 10 Gy/min at 1 m. The vehicle has only one rear axle but may in someconfigurations have more than one. The boom has a weight and whereinsaid boom is positioned such that the weight acts substantially over therear axle. The boom has a weight and wherein said boom is positionedsuch that the weight acts over the first area.

The boom has a lattice structure comprising a plurality of beam sectionsconnected by a plurality of nodes wherein said structure defines aninternal lattice area. The detector or sensor box is connected to anoutside the internal lattice area. The detector is positioned within theinternal lattice area. The vehicle comprises a plurality of targetswherein each of said targets is on a different part of said vehicle.

The inspection system further comprises a camera in data communicationwith a controller wherein said camera captures a movement of saidtargets and wherein said controller determines what portion of saidvehicle has moved based on the movement of said target. The controllerdetermines a speed of said vehicle based on said movement of saidtargets. The controller modulates a frequency at which X-ray data iscollected based upon said speed.

In another embodiment, the inspection system comprises a vehicle havinga first axle proximate to a front of said vehicle and one or more rearaxles proximate to a back of said vehicle wherein a first area isbounded by the rear axle extending to the front of said vehicle and asecond area is bounded by the rear axle extending to the back of saidvehicle; a radiological source; a boom, having a weight, rotatablyattached to said vehicle wherein said boom comprises a first verticalsection, a second vertical section and a horizontal section and whereinsaid weight is positioned to substantially act over said first area andnot said second area, wherein said system weighs 15,000 kg or less.

The system is capable of achieving radiological penetration of at least30 mm of steel. When fully deployed, the boom defines an area having aheight in a range of 2000 mm to 5300 mm and a width in a range of 2000mm to 4000 mm. The radiological source is attached to said vehicle andcapable of being moved from a first position to a second position,wherein each of said first and second positions are proximate to saidvehicle. The radiological source is an X-ray source is at least one of aX-ray generator with 100 kVp to 500 kVp tube voltage and 0.1 mA to 20 mAtube current, a 0.8 MV to 2.5 MV linear accelerator source with a doseoutput rate of less than 0.1 Gy/min at 1 m, and a 2.5 MV to 6 MV linearaccelerator source with a output dose rate in a range 0.1 Gy/min at 1 mto 10 Gy/min at 1 m. The boom has a lattice structure comprising aplurality of beam sections connected by a plurality of nodes whereinsaid structure defines an internal lattice area.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will beappreciated, as they become better understood by reference to thefollowing detailed description when considered in connection with theaccompanying drawings, wherein:

FIG. 1 illustrates the mobile inspection system according to oneembodiment of the present invention in transportation mode with the boomstowed on the vehicle;

FIG. 2 a shows three sections of a boom when fully deployed, accordingto one embodiment of the present invention;

FIG. 2 b shows a side view of one embodiment of a mobile inspectionvehicle with the boom in a stowed or folded condition;

FIG. 3 a depicts the functioning of a vertical support section of a boomaccording to one embodiment of the present invention;

FIG. 3 b depicts the functioning of a vertical support section of a boomaccording to another embodiment of the present invention;

FIG. 4 a depicts the mounting of a vertical support section of a boom onone embodiment of the mobile inspection vehicle in a deployed condition;

FIG. 4 b depicts the mounting of a vertical support section of a boom onone embodiment of the mobile inspection vehicle in a stowed condition;

FIG. 5 a illustrates a first configuration of an exemplary low masslattice structure which acts to reduce the weight of the boom, as usedin one embodiment of the present invention;

FIG. 5 b illustrates a second configuration of an exemplary low masslattice structure which acts to reduce the weight of the boom, as usedin one embodiment of the present invention;

FIG. 5 c illustrates a third configuration of an exemplary low masslattice structure which acts to reduce the weight of the boom, as usedin one embodiment of the present invention;

FIG. 5 d illustrates a fourth configuration of an exemplary low masslattice structure which acts to reduce the weight of the boom, as usedin one embodiment of the present invention;

FIG. 6 shows an exemplary design for a combined boom and detector box;

FIG. 7 presents an exemplary mechanism for folding and unfolding thehorizontal boom out from the vertical support;

FIG. 8 a shows an exemplary locking mechanism which is used when theboom is unfolded;

FIG. 8 b shows an exemplary locking mechanism which is used when theboom is unfolded;

FIG. 9 shows an additional boom support structure which can optionallybe used to help the boom deployment;

FIG. 10 shows another boom support structure;

FIG. 11 a illustrates a first space saving folding arrangement between ahorizontal boom and vertical boom, according to one embodiment of thepresent invention;

FIG. 11 b illustrates a second space saving folding arrangement betweenthe horizontal boom and vertical boom, according to one embodiment ofthe present invention;

FIG. 12 a illustrates an exemplary boom configuration which limits therotation of the X-ray source;

FIG. 12 b illustrates another exemplary boom configuration which limitsthe rotation of the X-ray source;

FIG. 13 a illustrates an exemplary mechanism for minimizing the swingingmovement of the X-ray source during boom deployment;

FIG. 13 b illustrates another exemplary mechanism for minimizing theswinging movement of the X-ray source during boom deployment;

FIG. 14 a illustrates a configuration for mounting the X-ray source;

FIG. 14 b illustrates an alternative configuration for mounting theX-ray source;

FIG. 15 a illustrates an exemplary locking mechanism for the boom andthe X-ray source;

FIG. 15 b illustrates another exemplary locking mechanism for the boomand the X-ray source;

FIG. 16 a illustrates an alignment of x-ray beam with the detectors;

FIG. 16 b illustrates another alignment of x-ray beam with thedetectors;

FIG. 17 a illustrates an exemplary configuration in which the scanningsystem of the present invention may be deployed;

FIG. 17 b illustrates another exemplary configuration in which thescanning system of the present invention may be deployed;

FIG. 17 c illustrates another exemplary configuration in which thescanning system of the present invention may be deployed;

FIG. 18 illustrates an exemplary sensor configuration for control of theX-ray system when operating in drive through mode according to oneembodiment of the present invention;

FIG. 19 shows an exemplary location of three vision targets, withrespect to a vehicle being inspected;

FIG. 20 shows the output from a scanning laser sensor as a function oftime;

FIG. 21 illustrates an embodiment where a process logic controller (PLC)is used to control the traffic control and X-ray control mechanism inthe scanning system of the present invention;

FIG. 22 illustrates an exemplary detector configuration according to oneembodiment of the present invention;

FIG. 23 illustrates another exemplary configuration wherein thedetectors are stacked, according to one embodiment of the presentinvention;

FIG. 24 shows a side elevation view of the mobile inspection vehicle ofthe present invention comprising an inspection pod in accordance withone embodiment;

FIG. 25 a shows top view of the mobile inspection vehicle of the presentinvention comprising an inspection pod in retractable state for travel;

FIG. 25 b shows top view of the mobile inspection vehicle of the presentinvention comprising the inspection pod in extendable state duringdeployment/operation;

FIG. 26 a shows a side elevation view of the mobile inspection vehicleof the present invention comprising inspection pod accessible to aninspector that can be seated above front wheel level;

FIG. 26 b shows top view of the mobile inspection vehicle of the presentinvention comprising inspection pod accessible to an inspector that canbe seated above front wheel level;

FIG. 27 shows top view of the mobile inspection vehicle of the presentinvention that has a rotatable bed;

FIG. 28 a shows an embodiment of boom structure/configuration to movepivot point of the boom forward of the rear wheels of the mobileinspection vehicle;

FIG. 28 b shows vertical support of the boom of FIG. 28 a extended infully vertical orientation along with the horizontal boom beingperpendicular to the vertical support;

FIG. 28 c shows the horizontal boom of the boom of FIG. 28 a beingrotated 90 degrees to be perpendicular to the long side of the mobilevehicle;

FIG. 28 d shows the vertical boom of the boom of FIG. 28 a being lowereddown to complete full deployment;

FIG. 29 a shows an embodiment of structure/configuration of boom, whenin stowed condition, in accordance with another aspect of the presentinvention;

FIG. 29 b shows vertical support of the boom of FIG. 29 a in verticalposition alongwith causing the horizontal boom to extend outwards in adirection perpendicular to the long edge of the vehicle;

FIG. 29 c shows the vertical boom of the boom of FIG. 29 a being lowereddown to complete full deployment;

FIG. 30 shows an embodiment of the boom structure/configuration of thepresent invention where the boom is deployed using an onboard crane;

FIG. 31 a shows an embodiment of the boom structure/configuration of thepresent invention comprising four components;

FIG. 31 b shows the two vertical support sections of the boom of FIG. 31a unfolded into an end-to-end configuration;

FIG. 31 c shows the horizontal boom of the boom of FIG. 31 a beingextended perpendicular to the long edge of the vehicle through 90degrees rotatory motion of the rotating platform;

FIG. 31 d shows an embodiment of the boom of FIG. 31 a where the uppervertical support is telescopically retractable/extendable to/from thelower vertical support;

FIG. 32 a shows an embodiment of the boom structure/configuration of thepresent invention comprising four components;

FIG. 32 b shows the two vertical support sections of the boom of FIG. 32a extended from horizontal (stowed position) to vertical position; and

FIG. 32 c shows the folded horizontal and vertical boom sections of theboom of FIG. 32 a being moved from horizontal to vertical orientation.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards a portable inspection systemfor generating an image representation of target objects using aradiation source, comprising a mobile vehicle; a detector arrayphysically attached to a single, movable boom having a proximal end anda distal end and at least one source of radiation wherein the radiationsource is fixedly attached to the proximal end of the boom andadjustable to a desired scanning height. The image is generated byintroducing target objects between the radiation source and the detectorarray, thereby exposing objects to radiation and subsequently detectingthe radiation. The boom can be unfolded from a first stowedconfiguration to a second deployed and operational configuration.

The system of the present invention is advantageous in that it providesa highly compact stowed configuration and has a low height, such thatthe highest part of the boom does not exceed the height of the drivecab, among other benefits. The inspection system of present inventionprovides a sturdy deployed configuration with the radiation source anddetectors readily aligned and a selectable scan angle position, and canbe converted from a stowed configuration to a deployed and operationalconfiguration in areas having limited horizontal and vertical clearance.Further, the inspection system of the present invention is capable ofusing either a small or a large LINAC, at both high as well as lowenergies. It may also be used with conventional sources of radiation.

In one embodiment, the present invention is directed toward a new boomconfiguration for the mobile inspection system, which addresses many ofthe issues that affect boom designs known in the art. The boom design ofthe present invention provides for a light weight scanning system, andthe boom can also be stowed in a compact manner. This makes theresulting mobile inspection vehicle highly maneuverable. Further, owingto its low axle weights, the mobile inspection vehicle is not subject toany road restrictions and can freely move across all territories in theworld.

It should be appreciated that the various mechanical and/or hydraulicmovements described herein can occur by manual manipulation of thephysical structures or hydraulic components or, as is preferred, bysignals transmitted by a controller. In one embodiment, a computingdevice with a graphical user interface is deployed to receive usercommands, transmit user commands to controllers that are in datacommunication with the various boom, bracket, winch, and/or hydrauliccomponents described herein, and receive data from the controllersindicative of the state of each of the various boom, bracket, winch,and/or hydraulic components described herein. Any computing device andcontroller system can be used, including laptops, mobile devices,desktop components, and X-ray control centers, and any form of datacommunication can be used, including wired or wireless communications.

FIG. 1 illustrates the mobile inspection vehicle 101 of the presentinvention in its normal transportation mode wherein the boom 102 isstowed on the vehicle. In the embodiment of FIG. 1, the inspectionvehicle 101 is a truck and the boom 102 in the stowed condition liessubstantially parallel to the bed 103 of the truck 101. The cab 104 ofthe truck is the highest part of the vehicle, and is typically at anapproximate height of 2.6 m from the ground to the highest point. Theboom 102 of the present invention is designed such that it is capable ofbeing folded to fit into a space lower than the height of the cab 104,that is, the highest part of the boom 102 does not exceed the height ofthe drive cab 104.

Persons of ordinary skill in the art should note that the maximumstandard overall vehicle dimension of a truck is typically 12 m (L)×2.5m (W)×4 m (H). However, the overall footprint of the mobile inspectionvehicle 101, of the present invention, with the compact boom 102 whenstowed thereon is 11 m (L)×2.5 m (W)×4 m (H) in accordance with oneembodiment. In an alternate embodiment the footprint of the vehicle 101is 8 m (L)×2.5 m (W)×2.6 m (H). The compact design of the vehicle 101with the stowed boom 102, of the present invention, offers asubstantially small overall size for the inspection vehicle when usedwith full size inspection tunnel of 4.6 m (H)×3.5 m (W) typically.

FIG. 2 a shows the boom when fully deployed. The boom comprises threesections: vertical support 201 a (connected to an X-ray source 201 d),horizontal boom 202 a, and vertical boom 203 a.

FIG. 2 b shows a side view of the mobile inspection vehicle 200 when itis in use, so that the boom is in deployed condition. As mentioned, theboom design of the present invention comprises three components—verticalsupport 201 b (connected to a X-ray source 203 d), horizontal boom 202 band vertical boom 203 b, which in the stowed condition can be foldedparallel to each other in a manner that the total space occupied by theboom is minimized. Since the boom is collapsible to a small volume (of1.5 m (H)×1.2 m (W)×5.0 m (L) in one embodiment) when stowed, theoverall height of the inspection vehicle is substantially reduced whenconfigured for transport. In one embodiment, the overall height of theinspection vehicle is about 2.6 m during transport when compared to aheight of 4.0 m for conventional vehicles. This further allows transportof the vehicle by aircraft (such as a C-130 military transporter) forrapid deployment where appropriate.

Referring now to FIGS. 2 a and 2 b together, the vertical supportsections 201 a, 201 b are manufactured using a strong material, which inone embodiment is steel. One of ordinary skill in the art wouldappreciate that other engineering materials such as carbon fibercomposite, aluminum or metal-composite structures may also be used.

An advantage of the boom structure/design of the present invention isthat the overall weight of the mobile inspection vehicle 200 issubstantially reduced. For example, a full size 4.6 m (H)×3.5 m (W)scanning-tunnel vehicle has a total weight of less than 25,000 kg,preferably less than 20,000 kg, and more preferably less than 15,000 kg.Persons of ordinary skill in the art would appreciate that this weightof the mobile inspection vehicle of the present invention issubstantially less when compared to a standard prior art truck thatwould typically weigh in excess of 25,000 kg. The lighter vehicle 200 ofthe present invention advantageously allows the vehicle/truck to operatewith a single front axle and a single rear axle. Conventional designsrequire at least 2 and often 3 rear axles to meet road regulations incertain countries/regions due to comparatively high weights of prior artvehicles. This system also can achieve a penetration of steel of morethan 90 mm, including 100 m, 120 mm, 150 mm, 180 mm and any incrementtherein.

Due to light weight, reduced number of axles and smaller overall size,the vehicle 200 of the present invention is much more capable ofoperating in rugged terrain than conventional prior art designs.

The functioning of the vertical support is further detailed in FIGS. 3 aand 3 b. As shown in FIG. 3 a, the vertical support 301 a is in a nearhorizontal position when not deployed. In one embodiment, the verticalsupport 301 a is at an angle in the range of 5 to 20 degrees to thehorizontal, when in stowed away position. A fixed point 302 a isprovided, around which the vertical support is enabled to pivot around.Thus for deployment, the position of the vertical support 301 a changesfrom near horizontal in FIG. 3 a to vertical as depicted by 301 b inFIG. 3 b.

The rotating action of the vertical support over the fixed point 302 a,302 b can be driven by a number of mechanisms including, but notrestricted to, one or more hydraulic rams, one or more electric motorsand associated gearboxes or a pulley drive system. It is preferable tobe able to lock the vertical support in place once it has been rotatedto the operating or stowed condition. This can be achieved by using, byway of example, conical pins (not shown) that pass through a supportstructure on the truck platform and into suitably located holes in thevertical support. One of ordinary skill in the art would appreciate thatother locking mechanisms known in the art can also be used in place ofor in addition to the example given.

In one embodiment, the X-ray source of the scanning system is mountedrigidly to the base of the vertical support such that it swings close tothe road surface once the vertical support is deployed. This isillustrated in FIG. 4 a. Referring to FIG. 4 a, the X-ray source 401 ais mounted in an offset position on the vertical support 402 a, suchthat the focal point 403 a of the X-ray source is in line with the X-raydetectors (not shown) that, in one embodiment, are mounted into thehorizontal and vertical boom structures (not shown in FIG. 4 a). In thisembodiment, the radiation source is positioned on the vertical support,which is a portion of the boom proximate to the truck, thereby offeringa better alignment between the source and the detectors. In conventionalinspection systems the radiation source is placed either on the truckitself, such as on the side or back of the truck, or on the distal endof the boom.

FIG. 4 b shows the X-ray source 401 b along with the vertical support402 b in the stowed position. It may be noted from FIG. 4 b thatsubstantially all of the weight of the vertical support 402 b acts over,is in alignment with, or is otherwise positioned over the rear axle 404b of the truck. Therefore, the vertical support 402 b is designed tominimize the overall weight of the mobile inspection vehicle in order toensure that the rear axle loading is kept to a reasonable level.

FIG. 28 a shows a boom structure/configuration to move pivot point 2806of the boom 2800 forward of the rear wheels 2804 of the mobileinspection vehicle 2810 in accordance with one embodiment of the presentinvention. In this embodiment, the boom 2800 comprises threecomponents—vertical support 2801, horizontal boom 2802 and vertical boom2803. The vertical support 2801 is mounted at its lower end to arotating platform 2805 which is securely fixed onto the inspectionvehicle chassis. An actuator is used to move the vertical support 2801from a substantially horizontal (when stowed) to a vertical orientationabout a hinge or pivot point 2806 which is attached to the rotatingplatform 2805. The horizontal boom 2802 is attached at one of its endsto the top of the vertical support 2801 using a pivot pin 2807. Duringdeployment, as an actuator extends the vertical support 2801, amechanical linkage maintains the same angle 2820 between the horizontalboom 2802 and vertical support 2801 as the angle 2815 between thevertical support 2801 and the rotating platform 2805. As a result, oneactuator is used to extend two booms in one action or substantiallyconcurrently.

FIG. 28 b shows the vertical support 2801 extended in fully verticalorientation with reference to the rotating platform 2805 along with thehorizontal boom 2802 also being perpendicular to the vertical support2801. Once the vertical support 2801 and horizontal boom 2802 aredeployed, as shown in FIG. 28 b, another actuator is used to rotate therotating platform 2805 through 90 degrees so that the horizontal boom2802 is perpendicular to the long side 2825 of the vehicle and extendingoutwards as shown in FIG. 28 c. Finally, as shown in FIG. 28 d, a thirdactuator is used to lower the vertical boom 2803 from a hinge point 2822at the distal end of the horizontal boom 2802.

Persons of ordinary skill in the art should note that the boomconfiguration of FIGS. 28 a through 28 d with the boom pivot point 2806being advantageously forward of the rear wheels 2804 reduces rear axleload substantially, thereby making the inspection vehicle 2810 easier todrive and more compact while providing greater protection for the X-raysource (that is mounted at the lower end/base of the vertical support).Lower weight also contributes to faster deployment of the system. In oneembodiment, the rear axle loading is below 9 tons for a full ladenvehicle.

FIG. 29 a shows a top perspective of another embodiment ofstructure/configuration of boom 2900 when in stowed condition, inaccordance with another aspect of the present invention. In thisembodiment, the boom 2900 comprises two components—a first componentcomprising vertical support 2901 and horizontal boom 2902 and a secondcomponent comprising vertical boom 2903. The vertical support 2901 andhorizontal boom 2902 are fixed at 90 degrees to each other to form onerigid assembly of the first component. The vertical boom 2903 is hingedfrom the distal end 2922 of the horizontal boom 2902.

The base of vertical support 2901 is hinged about a point 2906 which, inone embodiment, is at 45 degrees to the long edge 2925 of the side ofthe mobile vehicle 2910. Hinging the first component assembly (of thevertical support 2901 and horizontal boom 2902 at a fixed 90 degreesangle to each other) about the point 2906 causes the vertical support2901 to become vertical (during deployment), from its startinghorizontal aspect (when stowed), while simultaneously causing thehorizontal boom 2902 to extend outwards in a direction perpendicular tothe long edge 2925 of the vehicle, as shown in FIG. 29 b. Again, asillustrated in FIG. 29 c, once the vertical support 2901 and horizontalboom 2902 are in position, the vertical boom 2903 is lowered (using anactuator) about a hinge point at the distal end 2922 of the horizontalboom 2902 for complete deployment.

In one embodiment, it is preferred to have the vertical support 2901comprising a first portion which is fixed rigidly to the chassis of thevehicle 2910 and a second part which is hinged from the top of the firstpart. In this case, the hinge will advantageously extend over an angleof greater than 90 degrees so that the intersection between the verticalsupport upper part and the horizontal boom 2902 lies nearer to thevehicle chassis.

FIG. 30 shows yet another embodiment of structure/configuration of boom3000 in accordance with an aspect of the present invention. In thisembodiment, the boom 3000 comprises three components—vertical support3001, horizontal boom 3002 and vertical boom 3003. The boom 3000comprising these three components is stowed/loaded onto the back of themobile vehicle 3010. Vehicle 3010 is provided with a manually operatedcrane (not shown), such as a Hiab lift, which is used to lift the boomsections into place to form a static archway 3005 that is used indrive-through portal mode. During deployment, in one embodiment, anoperator lifts the vertical boom 3003 into position. Next, the operatorlifts the vertical support 3001 into position. Finally, the operatorlifts the horizontal boom 3002 into position such that it forms a‘bridge’ between the vertical support 3001 and vertical boom 3003. Atthis point, the operator can stow the crane and the boom is ready foruse.

In an alternate embodiment of the present invention, a positioning plate3015 is first placed into position thereby setting an exactpre-determined location for the base of the vertical boom 3003 relativeto the vehicle 3010. This positioning plate 3015 may be unfolded fromthe side of the vehicle or it may be placed into position using thevehicle mounted crane.

In a yet another alternative embodiment of the present invention, thevertical support 3001 and the vertical boom 3003 are each hinged fromtheir respective ends of the horizontal boom 3002 to form an assembly.The vehicle mounted crane is used to lift the assembly of threecomponents, from stowed condition, into approximate position fordeployment. With the assembly suspended on the crane, the verticalsupport 3001 and vertical boom 3003 are lowered from a substantiallyhorizontal position (that they were in when stowed) to a substantiallyvertical position using one or more electric or manually operatedwinches. The “inverted U” shaped boom 3000 is then lowered into itsoperating position and the crane removed to its storage position. Theboom 3000 is then ready for use. To stow the boom, the crane is used tolift the assembly up, the vertical support 3001 and vertical boom 3003are winched back to a substantially horizontal aspect and the thusassembly is stored back on the vehicle 3010.

FIG. 31 a shows still another embodiment of structure/configuration ofboom 3100 in accordance with another aspect of the present invention. Inthis embodiment, the boom 3100 comprises four components—lower verticalsupport 3101 a, upper vertical support 3101 b, horizontal boom 3102 andvertical boom 3103. The lower vertical support 3101 a is rigidlyattached to a rotating platform 3105 while an actuator rotates theplatform 3105 through 90 degrees in a plane perpendicular to the planeof the lower vertical support 3101 a. The upper vertical support 3101 bis attached to the lower vertical support 3101 a using a hinge (notshown) which can rotate the two vertical support sections by 90 degreeswith respect to each other. The upper vertical support 3101 b is rigidlyattached at 90 degrees to the horizontal boom 3102. The vertical boom3103 is hinged at the end 3122 of the horizontal boom 3102 which isfarthest from the upper vertical support 3101 b. In stowed condition,the upper vertical support 3101 b is folded substantially parallel tothe lower vertical support 3101 a.

To deploy the boom 3100, the two vertical support sections 3101 a, 3101b are unfolded into an end-to-end configuration (that is, to make asingle contiguous vertical support) as shown in FIG. 31 b. The rotatingplatform 3105 then rotates the boom 3100 through 90 degrees such thatthe horizontal boom 3102 extends perpendicular to the long edge of thevehicle 3110, as illustrated in FIG. 31 c. The vertical boom 3103 isthen unfolded into the vertical direction to complete deployment of theboom, as has been depicted in FIG. 31 a. Persons of ordinary skill inthe art would appreciate that the boom stow sequence is exactly oppositeto the above described deployment process.

In an alternate embodiment of the present invention, the upper and lowervertical support sections 3101 b, 3101 a respectively, are replaced by asingle vertical support so that the boom is deployed by simply firstrotating the boom and then unfolding the vertical boom 3103.

In another alternate embodiment of the present invention, upper verticalsupport 3101 b is telescopically retractable/extendable to/from thelower vertical support 3101 a as shown in FIG. 31 d and is not hinged tothe lower vertical support. In other words, for deployment the uppervertical support 3101 b is simply extended vertically upwards; theplatform 3105 rotated by 90 degrees and the vertical boom 3103 unfoldedinto vertical direction.

FIG. 32 a shows yet another embodiment of structure/configuration ofboom 3200, in stowed condition, in accordance with another aspect of thepresent invention. In this embodiment, the boom 3200 comprises fourcomponents—lower vertical support 3201 a, upper vertical support 3201 b,horizontal boom 3202 and vertical boom 3203 (visible in FIG. 32 c). Whenstowed for transport, the lower and upper vertical support sections 3201a, 3201 b respectively, are folded back on each other with rotatingjoints at each of their meeting ends 3204. The horizontal and verticalboom sections 3202, 3203 respectively, are each folded up to each otherwhile the horizontal boom 3202 is attached to the upper vertical support3201 b using a pin bearing 3206.

During deployment, an actuator is used to extend the two verticalsupport sections 3201 a, 3201 b from the horizontal (stowed position) tovertical position, as shown in FIG. 32 b. This causes the foldedhorizontal and vertical boom sections 3202, 3203 to move from thehorizontal to the vertical orientation, as illustrated in FIG. 32 c. Anactuator then folds out the horizontal boom 3202 to horizontal aspect,taking the vertical boom 3203 with it. Finally, the vertical boom 3203is lowered about its hinge point at the end 3222 of the horizontal boom3202. Boom stow adopts the same sequence but in reverse order.

Referring back to FIG. 32 a, in an alternate embodiment, the lowervertical support 3201 a is mounted on to a rotating platform (not shown)which can be used to set angle of the resultant scanning tunnel (whenthe boom 3200 is fully deployed) such that it is in the range,typically, of 75 to 90 degrees with respect to the long edge 3225 of thevehicle 3210. Advantageously, X-ray source is fixed to the underside ofthe rotating platform so that it tracks the required beam angle.

Persons of ordinary skill in the art should note that the plurality ofactuators, used for deployment or stow sequence of the boom structuresof FIGS. 28 through 32 of the present invention, may be electric motor(with rotary gearbox or linear screw rod actuators), hydraulic cylinderand lever, electric winch and cable (with removable or fixed endpoints), manual winch and cable (with removable fixed end points) or anyother actuators known to those skilled in the art. Where a rotatingplatform is used, boom deployment angles are adjustable in the range 75degrees to 90 degrees with respect to the scanning direction. Also,scanning aperture of the boom structures/configurations of FIGS. 28through 32 is typically 2000 mm (H)×2000 mm (W) minimum up to 5300 mm(H)×4000 mm (W) maximum. However, booms may alternatively be configuredwith a tunnel aperture outside these dimensions, such as 1000 mm (H),3000 mm (H), 6000 mm (H), 7000 mm (H), 1000 mm (W), 3000 mm (W), 4500 mm(W), 5000 mm (W), 5500 mm (W), 6000 mm (W), 6500 mm (W), and anydimensions in between.

Again, X-ray sources may be selected from any of the followingcategories:

-   -   X-ray tube and generator with 100 kVp to 500 kVp tube voltage        and 0.1 mA to 20 mA tube current, including X-ray sources with        160 kV and a penetration of 30 mm of steel.    -   0.8 MV to 2.5 MV linear accelerator source, including those        sources with a low output dose rate, typically less than 0.1        Gy/min at 1 m.    -   2.5 MV to 6 MV linear accelerator source with high output dose        rate, typically in the range 0.1 Gy/min at 1 m to 10 Gy/min at 1        m.    -   X-ray sources with penetration in excess of 120 mm of steel,        including 180 mm of penetration and any increment therein.    -   X-ray sources of 450 keV with a penetration of approximately 80        mm of steel.

In one embodiment, booms of the present invention are fitted with leador steel beam stops to reduce primary beam intensity at the extent ofthe surrounding radiation exclusion zone. The beam stop isadvantageously formed from lead with a thickness of 10 mm to 200 mmdepending on the energy of the X-ray source (the higher the energy, thethicker the primary beam stop). The booms are fitted with X-raydetectors to measure the transmitted X-rays from the source through theobject under inspection. Typically these detectors are formed from highdensity scintillation materials such as CdWO4, ZnWO4 or CsI with athickness in the range 0.3 mm to 50 mm depending on the energy of theX-ray source and the type of transmission measurement being made.

Additionally or optionally, the booms of the present invention arefitted with position sensors to provide feedback to an automated boomdeployment system. These sensors advantageously record when actuatormotion is complete at both ends of travel. In one embodiment, redundantsensors are deployed for such measurements to mitigate against sensorfailure.

In one embodiment for example, it is possible to complete boomdeployment in less than 2 minutes. Still faster times may be achievedwhen suitable strengthening components are fitted to the various boomsto mitigate actuator load. Further, boom stowage can also be completedin a similar duration of time.

The horizontal and vertical booms in the scanning system of the presentinvention are designed to contain as little material as possible. Thisallows for minimizing the weight, and hence reduces the tipping momenton the truck chassis. Several materials can be selected formanufacturing the booms, including steel, aluminum and compositematerials. One of ordinary skill in the art would appreciate that othersuitable light weight materials may also be used for this purpose. Inone embodiment, the boom design utilizes novel lattice structures toensure low mass in the boom. FIGS. 5 a through 5 d illustrate some ofthe exemplary low mass lattice structures which act to reduce the weightof the booms. The booms are further designed to include a light-tight,but compact housing for the X-ray detector assemblies.

Referring to FIG. 5 a, a section of the boom 501 a is shown incross-section. This boom structure utilizes square profile box sectioncomponents 502 a, or nodes, where three such box section components 502a are physically connected by a beam section 504 a. The sensor box 503 ais mounted to the side of the boom structure using metal supportbrackets (not shown) which attach to the triangular boom section 501 a.

FIG. 5 b shows an alternate design in cross-section, wherein the boomhas a square cross section 501 b with the sensor components 503 bmounted to the side and is made from four square profile box sectioncomponents 502 b where the components 502 b are physically connected bya beam section 504 b. One of ordinary skill in the art would appreciatethat it would also be possible to mount the sensor box 503 b within thesquare section 501 b. This, however, would result in a weakening of thestructure since the sensor box would need to form a “U” shape to allowunimpeded access of X-rays to the detectors.

FIG. 5 c shows a further design in which the detector box 503 c isprotected within a boom section comprised of two triangular supportframes 501 c of the boom. Each of the triangular support frames 501 ccomprises three profile box section components 502 c where thecomponents 502 c are physically connected by a beam section 504 c. Thetwo triangular sections are then further physically connected by beamsection 505 c.

FIG. 5 d shows another design of the boom in which “bulkheads” 504 d aremounted along the length of the boom which itself is formed from boxsection components 502 d. The sensor box 503 d in this case is encasedwithin the boom section.

One of ordinary skill in the art would appreciate that many otherstructures may also be used for the boom design to fulfill the objectiveof low mass, including, for example, round section tubing and castcomposite structures. The use of open frame lattice structures anddetector enclosures such as illustrated above not only makes the boomlightweight, but also makes it less wind resistant due to flow through,while still maintaining its rigidity.

The detector box used with the boom is required to be light, tight andimpervious to moisture. By way of good design, in one embodiment, thedetector box is combined with the boom structure to provide additionalstrength while also providing good access to the detector electronics.FIG. 6 shows an exemplary design for a combined boom and detector box.Referring to FIG. 6, the boom cross section 601 is extended to include abox section 602 for the X-ray detectors by connecting a beam section 608from one of its three profile box section components 609 where thecomponents 609 are physically connected by beam sections 610. Beamsection 608 physically connects to a box component 610, which thenconnects to a second box component 611. The detector electronics 603 areprovided with removable access covers 604 on one side and a removablefront cover 605 which is substantially transparent to the incomingX-rays 606. Further, a thin light-tight sheet covering 607 is providedto protect the rear side of the assembly and the side opposite to theaccess cover.

The lattice structures for boom and detector box illustrated in FIGS. 5and 6 can be fabricated using any suitable technique known to persons ofordinary skill in the art. As an example, it would be advantageous tofabricate the structure shown in FIG. 6 using a welded fabrication of 50mm×50 mm steel box section components with 2.5 mm wall thickness towhich 1 mm thick steel sheet is welded to form the detector enclosure,the detector cover and the access covers. Preferably, the detector boxis lined with a thermal insulation material to minimize thermal shock tothe detectors due to change in ambient temperature and also to help inreducing condensation that may occur in particularly cold climates.

In one embodiment of the system of present invention, only one commonengineering material is used for boom fabrication. This not only provescost-effective, but also ensures that uneven deformation in the boomdoes not occur under change in ambient temperature as may be the casewhen multiple materials are used in a boom design.

As mentioned earlier, one objective of the present invention is toensure a compact method of stowing the boom when not deployed. In orderto fold the horizontal boom out from the vertical support fordeployment, a number of mechanisms may be used. FIG. 7 presents anexemplary design for folding and unfolding boom sections, as used in oneembodiment of the present invention. Referring to FIG. 7, a singlehydraulic arm 701 is used to force the separation of the horizontal boom702 from the vertical support 703. The separation is facilitated bymeans of an intermediate rigid coupling 704 which rotates about a point705 on the vertical support.

In one embodiment, the unfolding action illustrated in FIG. 7 iscomplimented by a locking pin arrangement so that after deployment,hydraulic power can be lost without the boom folding back up. Anexemplary locking mechanism is shown in FIGS. 8 a and 8 b. Referring toFIGS. 8 a and 8 b, the horizontal boom 801 a is extended so that itfolds back above the vertical support 802 a. A dome shaped fixture 803a, 803 b attached rigidly to the top of the vertical support 802 aengages with locking plates 804 a, 804 b in the horizontal boom. Thelocking plates 804 a, 804 b are spring loaded such that they are pushedback when the boom is being folded by the dome shaped structure 803 a,803 b on the vertical support 802 a. Once the boom 801 a is deployedfully, the locking plates 804 a, 804 b snap back to their restingposition under the dome and the boom is locked in position. When theboom 801 a is to be stowed, the locking plates 804 a, 804 b can bewithdrawn using any suitable means, such as an electrical solenoid,electric motor, hydraulic actuator or any other device known to personsof ordinary skill in the art. A person of ordinary skill in the artwould also appreciate that many other locking mechanisms may also bedevised that provide a good balance between efficiency, cost and safety.

FIG. 9 shows another boom deployment structure. In this case, a firstend of a support bar 901 mounts to a bearing post 902, which connectsvertical support 903 to horizontal boom 904 in an angular configuration.Preferably the support bar 901 connects to the bearing post 902 at thebearing post pivot point 902 a. A second end of the support bar 901 hasintegrated therein a pulley 905, distal to the bearing 902. A cable 906connects to the horizontal boom 904 and passes over the pulley 905 andreturns back to a winch 907 which is mounted securely onto the verticalsupport 903. The winch 907 is operated during boom deployment and itacts to pull the horizontal boom 904 away from the vertical support 903.This mechanism eliminates the need for a hydraulic actuator, although ahydraulic support 910 may be employed for safety or backup. FIG. 9 alsoshows a horizontal boom lock 908, which may be used to sense when theboom deployment action has completed, so that the winch 907 can bestopped. Preferably a sensor is deployed in conjunction with thehorizontal boom lock 908 to sense a locking action and transmit thesensed locking action to a controller, which then communicates a stopsignal to the winch based upon the locked state.

A further enhancement of this invention is shown in FIG. 10. Referringto FIG. 10, the support bar 1001 is designed such that it can be rotatedout of the way once the horizontal boom 1002 has been stowed with thevertical support 1003 using the mechanism of the winch 1004 and cable1005. As the support bar 1001 is moved away, it serves to minimize thespace taken by the stowed boom.

Besides an efficient and compact folding arrangement between thevertical support and the horizontal section of the boom, the design ofthe present invention also incorporates a space saving foldingarrangement between the horizontal boom section and vertical boomsection, which is illustrated in FIGS. 11 a and 11 b. Referring to FIG.11 a, which shows the boom in a deployed state, at the junction of thehorizontal section 1101 a and vertical section 1102 a, a single foldinghinge arrangement 1103 a is used. A locking pin 1104 a is also providedwhich engages when the booms 1101 a and 1102 a are deployed fully, andacts to minimize mechanical wobble between the two booms. A singlehydraulic ram 1105 a is used to force the separation of the horizontalsection 1101 a from the vertical section 1102 a when unfolding isrequired.

The booms in folded or stowed state are illustrated in FIG. 11 b,wherein the hydraulic ram 1105 b works in conjunction with the hingearrangement 1103 b to fold the vertical boom 1102 b parallel to thehorizontal boom 1101 b.

One of ordinary skill in the art would appreciate that theaforementioned folding arrangement between the horizontal boom andvertical boom is provided as an example only, and several other designscan be implemented successfully.

Persons of ordinary skill in the art should also note that the boomstructures of the present invention allow requisite accuracy ofalignment so that X-ray energy levels of less than 2 MeV can be usedwhile also being adequate enough to penetrate 150 mm of steel, inaccordance with one embodiment. Further, as a result of the use of lowerX-ray energy levels, the embodiments of the present invention usesmaller Linacs when compared to prior art systems, thereby saving onoverall weight. As a further result of the cumulative weight savings,the present invention allows for an X-ray mobile inspection system withpenetration greater than 120 mm of steel, while weighing less than15,000 kg.

In a further aspect of this invention, the system is advantageouslyconfigured to avoid rotation of the X-ray source. This boomconfiguration which limits the rotation of the X-ray source isillustrated in FIGS. 12 a and 12 b. Referring to FIG. 12 a, an alternateX-ray source mounting is shown, with the boom structure in a stowedposition. Here, the X-ray source 1201 a is suspended from a bracket 1202a which is able to rotate about a point 1203 a fixed to the boomstructure 1204 a. FIG. 12 b illustrates the configuration with the boomstructure in a partially deployed position. Referring to FIG. 12 b, asthe vertical support structure 1204 b is raised for boom deployment, theX-ray support bracket 1202 b lowers the X-ray source 1201 b towards itsfinal operating point based upon a signal from a controller. Thisarrangement avoids the rotation of the X-ray source itself for boomdeployment.

In one embodiment, the swinging movement of the X-ray source during boomdeployment is also minimized by connecting a hydraulic damping systembetween the X-ray source bracket and the X-ray source itself. Thisarrangement is shown in FIGS. 13 a and 13 b. Referring to FIG. 13 a,which shows the system in an undeployed position, a hydraulic cylinder1301 a links the X-ray support bracket 1302 a and the X-ray source 1303a. Hydraulic cylinder 1301 a comprises fluid flow valves that are openedduring boom deploy and stow, such that the cylinder can change lengthunder the effect of gravitational pull on the X-ray source. Referring toFIG. 13 b, once the boom is deployed, the fluid valves of hydrauliccylinder 1301 b are closed, thereby locking the X-ray source 1303 b inposition along with the X-ray support bracket 1302 b. One of ordinaryskill in the art would appreciate that final adjustment of sourceposition can be made by extending or retracting the hydraulic cylinderas necessary, depending on the gradient of the ground on which the mainX-ray system is operating.

An alternative configuration for mounting the X-ray source isillustrated in FIGS. 14 a and 14 b. Referring to FIG. 14 a, the X-raysource 1401 a is mounted on a platform 1402 a, which is fixed rigidly tothe motionless part of the rotation joint 1403 a at the base of thevertical support 1404 a. The platform 1402 a is capable of being raisedand lowered for stowing and deployment respectively. Accordingly, theplatform is physically slidable relative to the truck. Referring to FIG.14 b, when the vertical support structure 1404 b is raised for boomdeployment, the platform 1402 b is concurrently lowered, thereby placingthe X-ray source 1401 b in its final operating position. The platform1402 b can be moved up, down, right, or left to position the sourcecorrectly for scanning. It should be appreciated that this motion can beeffectuated through a motor, engine, or hydraulic system, as is wellknown to persons of ordinary skill in the art.

In one embodiment, the platform on which the X-ray source is mounted isactuated using one or more hydraulic rams. Further, the hydraulic ram isoperated in conjunction with a geared chain drive so that the change inlength of the hydraulic ram can indirectly effect a change in positionof the X-ray source relative to the boom rotation point. A mechanicalarrangement is also provided to lock the relative positions of the boomand the X-ray source. One such exemplary locking mechanism is shown inFIGS. 15 a and 15 b. Referring to FIG. 15 a, which shows the system instowed position, the vertical support section 1501 a is provided with afirst locking element 1502 a, designed to mate with a corresponding, ormating, locking element or fixture 1503 a in the platform assembly 1504a. Thus, when the boom is deployed as shown in FIG. 15 b, the firstlocking element 1502 b and the corresponding, or mating, locking element1503 b are connected in a such a manner that the relative positions ofthe boom 1501 b and X-ray source 1504 b are fixed exactly. The lockingelement 1502 a, 1502 b rotates about a pivot point 1505 a, 1505 b tothereby move approximately 90 degrees and be received by thecorresponding, or mating, element 1503 a, 1503 b and thereby transitionfrom an unlocked state to a locked state. One of ordinary skill in theart would recognise that many alternative locking mechanisms arepossible in addition or in place of the exemplary locking mechanismdescribed above.

The X-ray system used with the mobile inspection system of the presentinvention is designed to allow use with a wide range of X-ray sources.The source of radiation may include conventional sources such as aradio-isotopic source or an X-ray tube, as well as Linear Accelerators(LINAC) or any other source known in the art capable of producing beamflux and energy sufficiently high to direct a beam to traverse the spacethrough an object under inspection to detectors at the other side, suchas a betatron. The choice of source type and its intensity and energydepends upon the sensitivity of the detectors, the radiographic densityof the cargo in the space between the source and detectors, radiationsafety considerations, and operational requirements, such as theinspection speed.

For example, the system of the present invention could employsource-based systems, cobalt-60 or cesium-137 and further employ therequired photomultiplier tubes (PMT) as detectors. If a linearaccelerator (LINAC) is optionally employed, then photodiodes andcrystals are used in the detector. One of ordinary skill in the artwould appreciate how to select a radiation source type, depending uponhis or her inspection requirements. In one embodiment, the system isoperated with a standard X-ray tube, which typically has energy in therange of 120 kVp to 450 kVp, for applications such as screening cars andsmall vehicles with or without passengers within the vehicle. In anotherembodiment, a low energy linear accelerator source, having a typicalenergy in the range of 0.8 MV to 2 MV, is used for the purposes ofscreening full size cargo in manifest verification. In yet anotherembodiment, a higher energy X-ray source, typically with an energy rangeof 2.5 MV to 6 MV, is used for scanning of full-sized containers. Inthis case, the image penetration capability of the X-ray source issuitable for detection of a range of illicit materials and devicesincluding narcotics, explosives, currency, alcohol, weapons andimprovised explosive devices. Those skilled in the art would furtherappreciate that the inspection system of the present invention may alsobe configured with a gamma-ray source such as Co-60 or Cs-137, toreplace the X-ray source.

Regardless of whether the radiation source is an X-ray generator or aLINAC, it is mounted on the same single boom as the detector arrays, sothat the need for sophisticated alignment systems each time the systemis deployed is eliminated. Thus, the radiation source and detectors aresubstantially permanently aligned on the same single boom. The featurealso allows for scanning at various degrees of offset, again without theneed to realign the LINAC or X-ray generator and detectors.

The X-ray system of the present invention is further designed to operatewith a very compact radiation footprint. As known in the art, X-rayscanning operates on the principle that, as X-rays pass through objects,the radiation gets attenuated, absorbed, and/or deflected owing to anumber of different physical phenomena that are indicative of the natureof the material being scanned. In particular, scattering occurs when theoriginal X-ray hits an object and is then deflected from its originalpath through an angle. These scatter radiations are non-directional andproportional to the total energy delivered in beam path. A narrowlycollimated beam will keep the overall radiation dose minimal andtherefore also reduce the amount of scatter radiation in the areasurrounding the scanner, thereby reducing the “exclusion zone”. Theexclusion zone is an area around the scanner in which general public arenot authorized to enter due to the possibility of their getting exposedto doses of radiations scattered during the scanning process. Theexclusion area is dependent upon the magnitude of current setting theintensity of the radiation source. The availability of a large enougharea for the “exclusion zone” around the scanner system is one of thefactors that influence the decision of positioning the mobile inspectionsystem.

Thus, in order to achieve a compact radiation footprint, and hence asmaller exclusion zone, it is necessary to collimate the radiation beamdown to a narrow fan beam of X-rays. This is illustrated in FIGS. 16 aand 16 b. In the embodiment shown in FIG. 16 a, the X-ray beam 1601 a iswide compared to the X-ray detector 1602 a, so that the detector 1602 ais always illuminated regardless of movement of the boom. Alternatively,as shown in FIG. 16 b, the detector 1602 b is wider than theilluminating beam 1601 b, thereby ensuring continuous illumination atthe detector regardless of movement of the boom. In either case, it isadvantageous to ensure that the boom design minimizes motion between thesource and sensors. The folding boom structure of the present inventioncan achieve this objective by mounting the X-ray source and X-raysensors to the same folding array structure so that relative motionbetween the three boom assemblies (horizontal boom, vertical boom andvertical support) is minimized. In this way the X-ray source (oraccelerator) and the X-ray detector are better aligned in the scanningsystem of the present invention, than in boom designs used with otherscanning systems.

Furthermore, the X-ray system of the present invention is designed tooperate in rugged conditions such as those employed in militaryapplications. As described earlier, the compact nature of the boomdesign, in particular its fold-flat capability, makes the mobileinspection system of the present invention uniquely suited to militaryapplications where it may be frequently required to transport the X-raysystem in its stowed condition in aircraft or helicopters. Such frequenttransportation is not feasible with other known boom configurations,where the height of the boom in its stowed condition is greater thanthat allowed for military transport. Further, the compact configurationlends a low center of gravity for better stability of the inspectionsystem during road transport, as there is often a need for driving theinspection system in hilly areas, border crossings, and steepmountainous areas.

The X-ray system used with mobile inspection system of the presentinvention is further intended to be deployed in a variety ofconfigurations. Some of these exemplary configurations are illustratedin FIGS. 17 a through 17 c. Referring to FIG. 17 a, the X-ray boomstructure 1701 a is demounted from a vehicle or truck (not shown) andused as a standalone trailer (shown as 1702 a) mounted device. Thetrailer mounted system of FIG. 17 a, which has wheels, can be used as ascanning system by attaching the trailer to a winch system which candrag the trailer backwards and forwards along a track. Alternatively,the trailer can be fitted with a speed sensing system so that thetrailer can be used to scan drive through traffic.

In an alternate configuration, illustrated in FIG. 17 b, the scanningsystem 1701 b is used as a standalone device that can be dropped off theback of a truck bed 1702 b. The standalone system of FIG. 17 b willnormally be used in a drive through mode although it may also be usedwith a winch to scan unoccupied vehicles (vehicle moves through staticgantry).

In a third configuration, as shown in FIG. 17 c, the scanning system1701 c can be fully integrated with a truck 1702 c for mobileapplications. This integrated system is typically used as a drive pastscanner in which the X-ray system is driven past a stationary object atcontrolled speed. However, in this case, it is also possible to operatethe system in a drive through mode. Here the boom base is attacheddirectly to the truck bed or to a trailer which is then integrated withthe truck bed. A suitable sensor configuration for control of the X-raysystem when operating in drive through mode is shown in FIG. 14. Thesensor system is used to execute two functionalities—traffic control andX-ray control.

In one embodiment, the mobile inspection vehicle 2400 of the presentinvention comprises an inspection pod 2405, placed on vehicle bed 2415along with stowed boom 2410, as shown in the side elevation view of thevehicle 2400 of FIG. 24. The inspection pod 2405 accommodates at leastone inspector who can view scanned X-ray images on a monitor while beingseated facing either the front or back of the vehicle. In oneembodiment, the inspection pod 2405 is sized to allow two imageinspectors to be seated back to back.

Referring now to FIGS. 25 a, b, the inspection pod 2505, in oneembodiment, is configured to be in retractable state and accommodatedcompletely on-board the vehicle 2500 ready for travel as shown in thetop view of FIG. 25 a and in extendable state when deployed for scanningas shown in the top view of FIG. 25 b. Persons of ordinary skill in theart should note that the inspection pod 2505 is sized to be comfortablyaccommodated on-board the vehicle 2500 such that when in retractablestate it is placed next to the stowed boom 2510. During operation, inone embodiment, when the boom 2510 is being deployed the inspection pod2505 is also simultaneously extended thereby keeping the overall timefor system deployment low.

In one embodiment, keeping in mind the overall compactness of thevehicle 2400 and the stowed boom 2410, the inspection pod 2405 is sizedat a footprint of about 2 m (L)×1 m (W)×2.5 m (H) when retracted (duringtravel) and of about 2 m (L)×2 m (W)×2.5 m (H) when in extended stateduring deployment/inspection. The sliding pod 2405 of the presentinvention enables a smaller footprint during travel while allowing forup to two inspectors to be seated, within, in extended state duringinspection or deployment.

In an alternate embodiment of FIGS. 26 a and 26 b, the inspection pod2605 is located on the mobile inspection vehicle 2600 such that theinspector is seated just above the wheel level 2615 with access to thepod 2605 through a hinged door (not shown). This configuration resultsin a lower overall inspection pod height. However, in this embodiment,the inspector is always seated within the pod. In the embodiment ofFIGS. 25 a and 25 b, the placement of the pod on the vehicle along withits height allows the inspector(s) to also stand up in the pod whenneeded.

FIG. 27 shows a yet another embodiment of the mobile inspection vehicle2700 of the present invention where the vehicle bed 2705, that supportsthe stowed boom 2710 along with the attached X-ray source 2715 can beswivelled or rotated by a plurality of angles in the horizontal plane ofthe bed. In one embodiment, the bed 2705 is capable of being swivelledto angles that allow deployment of the boom 2710 at customized anglesranging from, say, 70 to 90 degrees with respect to the direction ofscan. As would be evident to persons of ordinary skill in the art, therotation of the bed 2705 is typically controlled, in one embodiment,using electric motor or hydraulic actuator with accompanying sensors toconfirm rotation angle.

Referring now to FIG. 18, the sensor system comprises one or moremicrowave based radar speed camera 1801 mounted on the horizontal boom1802 of the scanning system 1800. The use of more than one redundantsensor is advantageous in this safety critical aspect of the design. Theradar sensors 1801 are used to sense the speed of a vehicle passingthough the X-ray aperture of the scanning system 1800 for inspection.For maintaining accuracy of measurement, the measured speed value isupdated at regular intervals. In one embodiment, the speed value ismeasured and updated approximately ten times a second so as to reflectthe speed of the vehicle passing though the scanning system as preciselyas possible. Also, for obtaining optimum scan results with a scanningsystem, there is generally a preferred speed at which a vehicle beingscanned should pass through, however the system of present inventionallows for a range of vehicle speeds. For example in one embodiment, anoptimum speed for a vehicle to pass through is 8 km/h, but acceptablevehicle speeds can range between 5 km/h and 10 km/h, with optimumresults.

The traffic control or the speed control mechanism of the presentinvention is designed to assist the driver of the vehicle beinginspected to drive through the system at an acceptable speed. In oneembodiment, a green traffic signal 1803 is presented to the driver whenthe speed of the vehicle is within acceptable range. If the driver slowsdown to below the lower acceptable speed limit, an amber colored uparrow 1804 is illuminated in addition to or in place of the greentraffic signal 1803. Alternatively, if the driver passes through at aspeed above acceptable upper speed limit, an amber-colored down arrow1805 is illuminated in addition to or in place or the green trafficsignal 1803.

The X-Ray control mechanism of the present invention allows forautomatic determination of the frequency and energy of the X-ray beamused for illumination of the vehicle or cargo being inspected. For thispurpose, the mechanism takes into account variables such as the start ofthe driver's cab, the end of the driver's cab, the starting point of thecargo to be inspected and the end point of cargo to be inspected. TheX-ray control mechanism comprises two redundant methods for imaging thetarget vehicle and determining the aforementioned variables. The firstmethod involves use of a scanning laser sensor 1806, which forms a twodimensional image of the height above the road surface of the vehiclebeing inspected. The second method of imaging the vehicle involves useof a machine vision camera 1807, which is located on the verticalsupport 1808. The machine vision camera 1807 detects vision targets 1809that are placed on the vertical boom 1810 on the opposite side. Thevision targets 1809 are located such that they correspond to differentparts of a cargo vehicle. Therefore, the simultaneous analysis of anumber of different targets can be used to identify different parts ofthe vehicle driving through the inspection aperture. By combiningsignals from the machine vision camera 1807 and the scanning lasersensor 1806, a robust control mechanism for switching on the X-ray beamaccording to the requirements can be implemented.

FIG. 19 shows an exemplary location of three vision targets (describedwith reference to 1809 in FIG. 18); with respect to a vehicle 1900 beinginspected. In this example, the vehicle 1900 is a truck. The firsttarget 1901 is located in line with the base of the vehicle flatbed 1901i. The second target 1902 is located in line with the cab of the vehicle1902 i, and the third target 1903 is located in line with the highestpart of the cargo 1903 i. A vision target can comprise any materialcapable of being readily identified by a camera and differentially seenby a camera relative to the vehicle surface.

FIG. 20 shows the output from the scanning laser sensor (described withreference to 1806 in FIG. 18) as a function of time. Four discretetransitions are indicated, representing various parts of the vehiclebeing scanned. The first transition A 2001 occurs when the start of thevehicle cab is detected. The second transition B 2002 occurs when theend of the vehicle cab is detected. The third transition C 2003 occursat the start of cargo, and the fourth transition D 2004 occurs at theend of cargo.

FIG. 20 further depicts (by means of marking with a tick) which of thethree vision targets detailed in FIG. 19 will be visible at eachtransition 2001, 2002, 2003, 2004, as detected by the laser heightscanner. Thus, as shown in FIG. 20, target3 2005, which is placed inline with highest part of the cargo, is visible during transitions A2001, B2002 and D 2004, which indicate start of the vehicle cab, end ofthe vehicle cab, and end of the cargo respectively. Similarly, target22006, which is located in line with the cab of the vehicle, is visibleduring transitions B2002 and D 2004, which indicate the end of thevehicle cab and end of the cargo, respectively. Target1 2007, which islocated in line with the base of the vehicle flatbed, is not visible inany of the transitions.

In one embodiment, a safety rated process logic controller (PLC) is usedto control the traffic control and X-ray control mechanism. This systemis illustrated in FIG. 21. A process logic controller (PLC) 2101 takesinputs regarding the vehicle speed from the radar sensors 2102, comparesthe values provided by the various radar sensors, and outputs trafficcontrol signals 2103 depending on the drive-through vehicle speed. Inone embodiment, the current vehicle speed is displayed on an electronicsign whose value is updated frequently, such as once per second.

The radar sensor data is also processed to provide a speed output to theX-ray system, comprising the X-ray source 2104 and the X-ray sensors2105. The PLC 2101 changes the frequency at which each line of X-raydata is collected, in proportion to the speed of the vehicle passingthrough the inspection area. For example, if the system normallyoperates at 300 Hz at 8 km/h, the frequency is increased to 375 Hz at adrive through speed of 10 km/h and reduced to 188 Hz at a drive throughspeed of 5 km/h. This kind of frequency modulation in accordance withthe vehicle speed results in delivery of a constant dose of radiationper unit length of the vehicle. This in turn ensures good image qualityand consistent scattered radiation dose to the driver and surroundingsystem operators.

The PLC 2101 also receives inputs from the scanning laser sensor 2106and the machine vision camera 2107, and controls the generation of X-Raybeam in accordance with the dimensions of the vehicle and cargo beinginspected. One of ordinary skill in the art would appreciate thatadditional sensors can be employed in the scanning system and interfacedwith the PLC 2101 to provide greater levels of safety and accuracy asrequired. For example, in one embodiment, a set of tire sensors can bedeployed with the scanning system, which would allow the system toproduce X-rays only when the driver's cab is safely past the primaryX-ray beam.

It is imperative that the X-ray sensor system is designed appropriate tothe application. In general, it is good practice to design a highspatial resolution sensor system, and to blur the image at the time ofdata display in order to create a low dose imaging system with goodcontrast resolution and penetration capability. This blurring can beachieved by mixing different proportions of the sharp original imagewith a blurred version until a good diagnostic image is obtained for thefeature of interest.

At any point in time when the radiation source is on, the detectors aresnapshots of the radiation beam attenuation in the object underinspection (OUI) for a particular “slice” of the OUI. Each slice is abeam density measurement, where the density depends upon beamattenuation through the OUI. The radiation detectors convert the lateralradiation profile of the OUI into electrical signals that are processedin an image processing system, housed in the inspection trailer, whilethe OUI is being conducted past the source and the radiation detector.

The X-ray image processing and control system, in an exemplaryembodiment, comprises computer and storage systems which record thedetector snapshots and software to merge them together to form an X-rayimage of the vehicle which may further be plotted on a screen or onother media. The X-ray image is viewed or automatically analyzed by OUIacquisition system such as a CRT or monitor that displays the X-rayimage of the vehicle to an operator/analyst. Alternatively, the OUIacquisition systems may be a database of X-ray images of desiredtargets, such as automobiles, bricks or other shapes that can becompared with features in the image. As a result of this imaging, onlyarticles that were not contained in the reference image of the containeror vehicle are selectively displayed to an operator/analyst. This makesit easier to locate articles that do not correspond to a referencecondition of the container or vehicle, and then to conduct a physicalinspection of those articles. Also, for high-resolution applications,the electronics used to read out the detector signals may typicallyfeature auto-zeroed, double-correlated sampling to achieve ultra-stablezero drift and low-offset-noise data acquisition. Automatic gain rangingmay be used to accommodate the wide attenuation ranges that can beencountered with large containers and vehicles.

The present invention generates a graphical representation, i.e., animage, of the densities of the contents of the vehicle under inspection.This allows for easy visual interpretation of the results of thescanning of the OUI. Advantageously, the preferred software system alsocauses the display of a reference image simultaneously with the imagegenerated in response to the vehicle under inspection, so that anoperator of the present embodiment can easily make a visual comparisonbetween what an object of the type being inspected should “look like”,and what the OUI actually “looks like”. Such “side-by-side” inspectionfurther simplifies the detection of contraband using the presentembodiment.

The present invention employs a detector configuration which provides agood compromise between image spatial resolution, contrast andpenetration performance and cost. This detector configuration isschematically illustrated in FIG. 22, and is particularly useful whenusing a low dose, low energy X-ray source such as a linear acceleratorin the energy range 0.8 MV to 2 MV. Referring to FIG. 22, a two rowsensor arrangement is shown, in which both rows of sensors—2201 and2202, are irradiated by the X-ray beam. The pulsed X-ray beam (notshown) from the linear accelerator is timed such that each X-ray pulseoccurs when the object relative to the X-ray beam moves exactly by onedetector spacing. This means that the two adjacent detector samples canbe summed with the advantage of doubling the detected signal, while atthe same time reducing the X-ray photon noise by a square root of two.This arrangement enhances the signal to noise ratio in the scanningsystem of the present invention by around 40% as compared to systemsusing a single row of detectors.

It may be noted that when using the aforementioned detector arrangement,the design of the present invention also ensures that the boom itself isvery stable, so that the X-ray beam can be collimated tightly in orderto minimize the operational radiation footprint of the X-ray scanningsystem.

Such a detector configuration has the benefit of allowing a doubledrive-through rate where the vehicle moves exactly two detector widthsthrough the X-ray beam between X-ray pulses. This can increase thenominal drive through speed from for example, 8 km/h to 16 km/h, albeitwith a reduction in image penetration performance but with no reductionin spatial resolution.

Such a detector configuration has a further benefit of allowingdual-energy imaging when provided with an X-ray linear accelerator thatis capable of interleaved energy operation. That is, the system can workwith small and large accelerators at low and high energy. For example,two energies—of the order of 3 MV and 6 MV may be used in adjacentpulses. In one embodiment, each pulse is delivered after the object tobe inspected has passed exactly one detector width through the X-rayinspection aperture. The vehicle will therefore have completely passedthe detector after exactly two X-ray pulses, one at low energy and oneat high energy. Although the penetration performance is somewhatcompromised since only one measurement is made at each beam energy andnot two, however, this information is very useful in providing materialsdiscrimination performance.

In one embodiment, where the present invention employs dual source-basedsystems, it further employs the required photomultiplier tubes asdetectors. In one embodiment, ⁶⁰Co is used as a first gamma ray sourceand has a high specific activity of the order of 11.1 TBq (300 Ci) and alinear dimension of the active area of 6 mm. In one embodiment, thesecond gamma ray source is a 1.0, 1.6 or 2.0 Curie shutteredmono-energetic source of ¹³⁷ Cs gamma rays, having 662 keV energy.

In a further embodiment of the present invention, stacked detectors canbe used to provide further spectral deconvolution of the X-ray beam.This is illustrated in FIG. 23. Referring to FIG. 23, one set of lowenergy detectors 2301 are located in the path of the X-ray beam 2302,and a second set of detectors 2303 are shadowed from the X-ray source bythe first set of detectors 2301. In this case, the second set ofdetectors 2303 can see only the high energy part of the X-ray beam. Thisinformation can be effectively used to provide materials discriminationcapability in the scanning system of the present invention. In anotherembodiment, both stacked detectors and an interleaved X-ray source maybe used to provide an enhanced level of materials discriminationperformance.

In one embodiment, additional collimation is advantageously providedadjacent to the detector array. This may be achieved for example, byplacing thin sheets of tungsten or other suitably attenuating materialparallel to the direction of the X-ray beam but orthogonal to thedetector array. Such collimation acts to reduce the effect scattercreated in the detector housing assembly as well as scatter generatedwithin the object under inspection.

One of ordinary skill in the art would appreciate that spatialresolution that can be achieved in the X-ray image depends on thedetector configuration chosen and on the focal spot size of the X-raysource. In one embodiment, the detectors are configured with an elementsize in the range of 1 mm to 10 mm and the X-ray source has a focal spotdimension in the range of 0.5 mm to 3 mm. This results in a spatialresolution generally between 1 lp/cm and 5 lp/cm.

Further, the penetration performance depends on the energy of the X-raysource. For the system of present invention, the penetration performanceis typically in the range of 20-100 mm for X-ray sources below 450 kVp,between 100 mm and 200 mm for sources in the range of 450 kVp to 2 MVand between 200 mm and 400 mm for sources in the range of 2 MV to 6 MV.

In a further aspect of this invention, the X-ray imaging system isintegrated with a passive gamma detection system. In this case, one ormore large area detectors are located adjacent to the X-ray detectorarrays in the horizontal and vertical booms and along the full length ofthe vertical support. This arrangement provides a large surface area forgamma-ray detection. In one embodiment, the large area gamma raydetectors are advantageously assembled from organic scintillationmaterials such as an organic plastic scintillator or using in-organicscintllator materials such as NiI(T1) of CsI(T1). The gamma-raydetectors are advantageously also configured to allow them to beswitched off while the X-ray source is switched on and then re-enabledonce the X-ray beam is switched back off again. This is particularlyimportant when using a pulsed linear accelerator source for X-rayimaging where the gamma-ray detectors can be rendered inactive duringthe X-ray pulse and re-activated immediately following the pulse.

In another configuration, the secondary detectors can provide asimultaneous backscatter imaging capability. In this case, X-rays fromthe main imaging beam may backscatter into a series of detectors whichare mounted upon the vertical support. In one embodiment, the detectorsmay be provided with additional collimation in order to restrict thedirection from which backscattered radiation is received. Thebackscatter image, being correlated in spatial position with the X-raytransmission image, can provide additional information about thepresence, or otherwise, of low atomic number materials that are locatedat, or near to, the surface of the object under inspection adjacent tothe X-ray source.

The novel design and the aforementioned features of the presentinvention enable a cost-effective, safe and completely self-containedscanning system that can be used for non-intrusive inspection ofcontainers, trucks and passenger vehicles. The road mobile configurationand low weight design of the present scanning system allows fortransport on difficult terrain, such as in border areas, apart fromlocal roads and highways. Further, since the system takes a very shorttime (around 15 minutes) to be fully deployed, and there is lessoperational space required for deployment, it facilitates operation atmultiple locations and is efficient at performing high throughputinspections. The system can scan cargo in mobile and stationary mode andthe minimal operating area makes it well suited for limited spaceapplications. Some of the other features and benefits of the mobileinspection system of the present invention are:

-   -   The boom design allows for more precise linear accelerator to        detector alignment. The folded array detector box configuration        shortens the distance between X-ray source and the detector,        which increases penetration and provides no corner cutoff with        less image distortion.    -   The unique scanning boom assembly can be deployed at either a        ninety or a eighty degree offset to the vehicle inspected. This        allows maximum flexibility in the setup of operational area        while providing excellent hidden compartment and false wall        detection capabilities.    -   One person may deploy the boom with a single button; thus the        system is safe, reliable and simple. Stowing the boom is done in        the same manner.    -   The scanning system includes a plurality of CCTV cameras, which        provide a view of the operating zone and help maintain safety.    -   Two modes of operation are supported—Mobile and Portal, which        allow for inspection of stationary as well as moving cargos,        respectively.    -   A training mode is provided, which offers images from a training        library for simulated scans during inspector training    -   The modular design of the scanning boom assembly and imaging        system allows it to be easily adapted to truck chassis from        several different manufacturers. This allows local trucks to be        utilized in various countries and simplifies vehicle        maintenance.

The above examples are merely illustrative of the many applications ofthe system of present invention. Although only a few embodiments of thepresent invention have been described herein, it should be understoodthat the present invention might be embodied in many other specificforms without departing from the spirit or scope of the invention. Forexample, other configurations of cargo, tires, tankers, doors, airplane,packages, boxes, suitcases, cargo containers, automobile semi-trailers,tanker trucks, railroad cars, and other similar objects under inspectioncan also be considered. Therefore, the present examples and embodimentsare to be considered as illustrative and not restrictive, and theinvention is not to be limited to the details given herein, but may bemodified within the scope of the appended claims.

1. An inspection system comprising: a. A vehicle having a first axleproximate to a front of said vehicle and a rear axle proximate to a backof said vehicle wherein a first area is bounded by the rear axleextending to the front of said vehicle and a second area is bounded bythe rear axle extending to the back of said vehicle; b. A radiologicalsource; and c. A boom movably attached to said vehicle wherein said boomcomprises a first vertical section, a second vertical section and ahorizontal section and wherein, when fully deployed, said boom definesan area having a height in a range of 2000 mm to 5300 mm and a width ina range of 2000 mm to 4000 mm; d. Wherein said system weighs less than20,000 kg and is capable of achieving radiological penetration of atleast 30 mm of steel.
 2. The inspection system of claim 1 wherein saidradiological source is attached to said vehicle.
 3. The inspectionsystem of claim 1 wherein said radiological source is attached to saidvehicle but not attached to said boom.
 4. The inspection system of claim1 wherein said radiological source is an X-ray source is at least one ofa X-ray generator with 100 kVp to 500 kVp tube voltage and 0.1 mA to 20mA tube current, a 0.8 MV to 2.5 MV linear accelerator source with adose output rate of less than 0.1 Gy/min at 1 m, and a 2.5 MV to 6 MVlinear accelerator source with a output dose rate in a range 0.1 Gy/minat 1 m to 10 Gy/min at 1 m.
 5. The inspection system of claim 1 whereinsaid vehicle has only one rear axle.
 6. The inspection system of claim 5wherein said boom has a weight and wherein said boom is positioned suchthat, upon movement of said boom, the weight acts substantially over therear axle.
 7. The inspection system of claim 1 wherein said boom has aweight and wherein said boom is positioned such that, upon movement ofsaid boom, the weight acts over the first area.
 8. The inspection systemof claim 7 wherein said boom has a lattice structure comprising aplurality of beam sections connected by a plurality of nodes whereinsaid structure defines an internal lattice area.
 9. The inspectionsystem of claim 8 wherein a detector is connected to an outside theinternal lattice area.
 10. The inspection system of claim 8 wherein adetector is positioned within the internal lattice area.
 11. Theinspection system of claim 1 wherein said vehicle comprises a pluralityof targets wherein each of said targets is on a different part of saidvehicle.
 12. The inspection system of claim 11 further comprising acamera in data communication with a controller wherein said cameracaptures a movement of said targets and wherein said controllerdetermines what portion of said vehicle has moved based on the movementof said target.
 13. The inspection system of claim 12 wherein saidcontroller determines a speed of said vehicle based on said movement ofsaid targets.
 14. The inspection system of claim 13 wherein saidcontroller modulates a frequency at which X-ray data is collected basedupon said speed.
 15. An inspection system comprising: a. A vehiclehaving a first axle proximate to a front of said vehicle and at leastone rear axle proximate to a back of said vehicle wherein a first areais bounded by the rear axle extending to the front of said vehicle and asecond area is bounded by the rear axle extending to the back of saidvehicle; b. A radiological source; and c. A boom, having a weight,movably attached to said vehicle wherein said boom comprises a firstvertical section, a second vertical section and a horizontal section andwherein said weight is positioned to substantially act over said firstarea and not said second area; d. Wherein said system weighs 20,000 kgor less.
 16. The inspection system of claim 15 wherein said system iscapable of achieving radiological penetration of at least 30 mm ofsteel.
 17. The inspection system of claim 15 wherein, when fullydeployed, said boom defines an area having a height in a range of 2000mm to 5300 mm and a width in a range of 2000 mm to 4000 mm
 18. Theinspection system of claim 15 wherein said radiological source isattached to said vehicle and capable of being moved from a firstposition to a second position, wherein each of said first and secondpositions are proximate to said vehicle.
 19. The inspection system ofclaim 18 wherein said radiological source is an X-ray source is at leastone of a X-ray generator with 100 kVp to 500 kVp tube voltage and 0.1 mAto 20 mA tube current, a 0.8 MV to 2.5 MV linear accelerator source witha dose output rate of less than 0.1 Gy/min at 1 m, and a 2.5 MV to 6 MVlinear accelerator source with a output dose rate in a range 0.1 Gy/minat 1 m to 10 Gy/min at 1 m.
 20. The inspection system of claim 15wherein said boom has a lattice structure comprising a plurality of beamsections connected by a plurality of nodes wherein said structuredefines an internal lattice area.